Sheet feeding and adhesive coating method and apparatus



24, 1966 w. F. ANDRESEN, JR, ETAL 3,252,701

SHEET FEEDING AND ADHESIVE COATING METHOD AND APPARATUS Filed July 2, 1963 '7 Sheets-Sheet 1 Fig May 24, 1966 w. F. ANDRESEN, JR., ETAL 3,252,701

SHEET FEEDING AND ADHESIVE COATING METHOD AND APPARATUS Filed July 2. 1963 '7 Sheets-Sheet 2 y 1966 w. F. ANDRES-EN, JR. ETAL 3, 2,701

SHEET FEEDING AND ADHESIVE COATING METHOD AND APPARATUS Filed July 2. 1963 7 Sheets-Sheet 5 May 24, 1966 W. F. ANDRESEN, JR, ETAL SHEET FEEDING AND ADHESIVE COATING METHOD AND APPARATUS Filed July 2, 1963 '7 Sheets-Sheet 4 May 24, 1966 w. F. ANDRESEN, JR., ETAL 3,252,701

SHEET FEEDING AND ADHESIVE COATING METHOD AND APPARATUS Filed July 2.. 1965 7 Sheets-Sheet 5 y 1966 w. F. ANDRESEN, JR. ETAL 3,252,701

SHEET FEEDING AND ADHESIVE COATING METHOD AND APPARATUS Filed July 2. 1963 '7 Sheets-Sheet 6 334 Z :2 240 M 25/ 235a May 24, 1966 w. F. ANDRESEN, JR, ETAL 3,252,701

SHEET FEEDING AND ADHESIVE COATING METHOD AND APPARATUS Filed July 2. 1963 7 Sheets-Sheet 7 :lllllv IIIHIIHII Tllllllll l IIIIIIIIIllllIJ GIIIIIIIIIHIIIIIII IIIIIIIII 5 United States Patent 3,252,701 SHEET FEEDING AND ADHESIVE CGATING METHOD AND APPARATUS William F. Andresen, Jru, Chalfont, and Robert A. Sterner,

Oakford, Pa, assignors to FMC Corporation, San Jose,

Calif., a corporation of Delaware Filed July 2, 1963, Ser. No. 292,423 19 Claims. (Cl. 271-1) This invention relates to a feeding and adhesive coating system and has for an object the provision of methods of and apparatus for feeding and adhesively coating Wrappers, sheets, labels or equivalent, hereinafter generically termed sheets.

The present invention is particularly applicable to sheet gluing machines such as used in the manufacture of set-up paper boxes. In preparing the wrappers for application to set-up boxes, it is necessary to apply adhesive or glue to one surface thereof. Thi is normally accomplished in a gluing machine which is associated with a suction conveyor for delivering the adhesive coated sheets to a box wrapping machine where the sheets are Wrapped around a set-up box. Such sheets are frequently of very thin flexible paper and thus present a problem in separating the outermost sheet from a stack of sheets so that the sheets may be fed one at a time through the gluing machine. Since the sheets normally have flaps extending from the central portion thereof which are adapted to cover the side walls of the box, such flaps present a problem in feeding the sheets into the feed rolls of the gluing machine.

It is an object of the present invention to provide an improved feeding system for controlling the side flaps of the sheets and prevent the corners from being folded under or over as they are fed into the gluing machine.

It is a further object of the invention to provide a sheet feeding system which will have increased table stack height capacity.

It is another object of the invention to provide an improved stack height sensing system which accurately senses the height of the stack without interfering with the feeding of the sheets.

It is va further object of the invention to provide a machine with a removable lower sheet guide plate to permit ease of cleaning any glue which might accumulate thereon.

It is a further object of the invention to provide a sheet feeding and coating system which permits feeding the sheets while manually operating the machine.

In accordance with the present invention, the sheets are fed one by one from a stack to a gluing machine. A blast of air is applied horizontally of the leading edges of the sheets at the top of the stack for separation of the top sheets at its leading edge. Suction is applied to the upper surface of the leading end of the top sheet to lift it from the stack and a force is applied to the lower surface of the leading end of the sheet after the leading end of the sheet has been lifted by the suction applied to the upper surface or moving the leading end of the sheet between the upper and lower guide plates and a pair of feed rolls. In order to support the side flaps of the sheet as they move toward the throat formed by the upper and lower guide plates, air pressure is applied to the lower surface of the side flaps to force the side flaps against the upper guide plate and thus insure that they are not folded over when they enter between the guide plates. The air pressure applied to the lower surface of the sheet is in the form of an air blast directed in an angular direction upwardly and toward the center of the sheet and comprises a wide band of air extending for a substantial distance at the opposite edges of the sheet thereby providing support for sheets having side flaps of substantial Width.

Further in accordance with the invention, the sheets are supported on a table which is provided with a trolley arrangement which moves up and down on both sides of the machine, the upward movement of the trolley being controlled automatically by a stack height sensing system which senses the height of the stack at the rear rather than at the front to avoid pressing the front edges of the sheet and interfering with their separation from the stack as they are fed into the machine. The table for the sheets is cantilevered with respect to the trolley and enables the table to support a substantially heavier stack of sheets than on prior machines.

For a more detailed disclosure of the invention and for further objects and advantages thereof, reference is to be had to the following description taken in conjunction with the accompanying drawings, in which:

FIG. 1 is a front elevational view of a sheet gluing machine embodying the present invention;

FIG. 2 is a side elevation taken in direction of the arrows 22 in FIG. 1;

FIG. 3 is a fractional side elevation of a suction roll and actuator therefor taken in the direction of the arrows 3-3 in FIG. 1;

FIG. 4 is a fractional side elevation taken along the plane 44 in FIG. 1;

FIG. 5 is a sectional view taken along the plane 5-5 in FIG. 1;

FIG. 6 is a fractional view on enlarged scale showing parts in FIG. 5;

FIG. 7 is a fractional perspective view taken from the rear of the machine shown in FIG. 1;

FIG. 8 is a fractional side elevation looking in the direction of the arrows 8-8 in FIG. 1;

FIG. 9 is a sectional view looking in the direction of the arrows 99 in FIG. 2;

FIG. 10 is a top plan view of the stack height sensing assembly looking in the direction of the arrows 10-10 in FIG. 2;

FIG. 11 is a diagrammatical view of the drive for the sheet gluing machine; and

FIG. 11a is a sectional view of the one cycle clutch C diagrammatically illustrated in FIG. 11.

Referring to FIGS. 1 and 11, there is shown a sheet gluing machine 10 embodying the present invention. The machine 10 includes a frame comprising a pair of vertical side plates 11 and 12 joined together at their lower ends by a pair of cross-bars 13, only one of which is shown in FIG. 1. Supported on the cross-bars 13 is a base plate 14 which in turn supports a drive motor 15 for operating the machine 10. The drive motor 15 operates through a variable speed belt drive including a pulley unit 16, a belt 17 and a pulley 18, the latter being carried on a countershaft 19. Also mounted on countershaft 19 is a sprocket 20 which is connected by a chain 21 to a sprocket 22 carried by a second countershaft 23. The shaft 23 is supported by a pair of bearings 24, 24 respectively carried by the side plates 11 and 12, FIG. 1. The ends of the shaft 23 extend through the side plates 11 and 12 and as may be seen in FIG. 2, the end of shaft 23 there shown is provided with a sprocket 25 around which passes a double strand chain 26, the latter also passing around a sprocket 27 on a shaft 28, FIGS. 2 and 11.

As may be seen in FIG. 11a, the sprocket 27 is carried by a flange 30 which is attached to a hub 31 and is free to idle on the shaft 28. While the sprocket 27 is continuously driven from the motor 15, it is adapted to impart one revolution per cycle of the machine to shaft 28 by means of a one revolution clutch C, FIGS. 11 and 11a. For convenience of illustration, the one revolution clutch C and its associated parts are shown to the right of sprocket 27 in the diagrammatical view of FIGURE 11 although it will be appreciated that these members are actually physically located on shaft 28 to the left of the sprocket 27. As may be seen in FIG. 2, there is a push solenoid 34 which is adapted to be energized once during each cycle of operation of the machine 10. In box wrapping systems, the gluer is generally tripped from the cam shaft of the box wrapping machine such as disclosed in U.S. Patent No. 2,705,905. The tripping may be done mechanically or electrically. When the coil of solenoid 34 is momentarily energized, the actuator rod 34a of the solenoid which is connected at its upper end to the horizontal lever 35 will move upwardly causing the lever 35 to pivot in a clockwise direction about a pin 36. This will lift a dog 37 which is carried by lever 35, FIG. 11a, out of engagement with driving pin 39 thus permitting the spring 40 to urge the pin 39 into engagement with the slot 30a in flange 30. The flange 30 has a plurality of equally spaced slots 30a around its central axis so that the driving pin 39 can readily be inserted into one of the slots 30a under the bias of spring 40. When the pin 39 is so inserted in one of the slots 30a, the shaft 28 will make one revolution in a clockwise direction as shown in FIG. 2 by the arrow. At the end of the revolution, the lever 35, which is no longer held up by the solenoid 34, causes the dog 37, FIG. 11a, to engage an angular face on the pin 39, camming the latter out of the slot 30a in the flange 30 thereby disconnecting the drive from the sprocket 27 to shaft 28. In order that the shaft 28 will stop immediately at the end of one revolution and not overtravel, the hub assembly 42 which carries the driving pin 39, also carries a stop pin 43, FIG. 11a. As may be seen in FIG. 2, the stop pin 43 is adapted to move in between a pair of latch members 44, 44a and prevent overthrowing or rebound of the hub 42. The latch members 44 and 44a are pivotally carried by the lever arm 35. The lever arm 35 is supported at its right-hand end, FIG. 2, through pin 36 by a lever 46 which is pivoted on a stud 47 carried by the vertical frame plate 11. The lever 46 hangs down between a pair of adjustable stops 48 and 480, the lever 46 being biased against the left-hand stop 48 by means of a spring 49. The purpose of this arrangement is to soften the blow of the disengagement of the clutch at the end of each revolution of shaft 28.

As may be seen in FIGS. 1 and 11, the shaft 28 which turns one revolution per cycle of the machine carries two pairs of earns 52, 52, 53, 53 and a fifth cam 54. The pair of cams 52, 52 operate a suction roll 56. FIGS. 3, 4, 6 and 7, the cams 53, 53 operate the feed rolls 57 and the cam 54 operates a valve in the suction line for the suction roll 56, as now to be described.

In regard to operation of the suction roll 56, each of the cams 52 is associated with a cam follower 60 carried by a lever 61, FIG. 3, the latter being carried by a shaft 62. Also carried on shaft 62 is a vertical lever 63 having at its upper end a link 64 which connects with the suction roll 56. The lever 61 carries an arm 65 which in turn supports an adjustable threaded member 66, one end of which engages the rear edge of vertical lever 63. By adjusting the screw member 66, it is possible to position the arm 63 and thus the suction roll 56 relative to the stack of sheets S. When the cam 52 rotates, as indicated by the direction of the arrow in FIG. 3, the vertical lever 63 will be caused to rotate about pivot 62 against the bias of a tension spring 69 which is connected to a hanger 70. As the lever 63 reciprocates, due to rotation of cam 52, it transmits angular motion to the suction roll 56 through the link 64. The angular motion of suction roll 56 is produced by a pair of spaced tracks 71, 72, FIGS. 1 and 7, which are inclined upwardly at the opposite ends of suction roll 56 and are adapted to receive therebetween rollers 73 carried by these ends. The suction roll 56 in addition to reciprocating also oscillates or rotates as it is reciprocated. Oscillation is imparted to the suction roll 56 through a rack 74 carried by the side plate 12 of the machine and a pinion 75 carried by the suction roll 56. The pinion is rotatable with the suction roll '56 so that the angular relationship between the suction tip 56a and the top of the paper stack S, FIGS. 3 and 4, may be varied. When properly positioned, the pinion 75 is clamped to the suction roll 56 and suction is introduced to the suction roll 56 through a flexible hose 80, FIG. 4, which is connected to a valve 81. The other side of the valve 81 is connected to a flexible hose 82 which in turn connects to an individually motor driven vacuum pump P, FIG. 1. The cycling of the vacuum suction roll 56 is controlled by the cam 54 on shaft 28 through the roller and lever combination 85-89. The upper end of the vertical lever 87 has connected thereto a thin metal plate 90 which is adapted to cover the open port 81a in valve 81, FIGS. 1 and 4.

When the suction roll 56 is in the full line position as shown in FIG. 3, the suction valve 81 is closed as shown in FIG. 4. This applies suction to the roll 56 so that it may pick up the leading flap of a sheet S. The suction roll 56 is adapted to reciprocate between the full line and phantom line positions shown in FIG. 3 under the influence of the cams 52 carried by shaft 28. As pointed out above, the inclined tracks 71 and 72 guide the suction roll 56 in its inclined movement and the rack 74 and .pinion 75, FIG. 7, cause the suction roll 56 to oscillate or rotate during its inclined movement thereby causing the suction port 56a in suction roll 56 to move from its down position in FIG. 3 to its up position in FIG. 6.

Referring to FIG. 5 there is shown a glue pan 92, suspended in a hot water pot 92a, from which glue is picked up by a glue drum 93 and applied to a glue distributing roll 94. The amount of glue deposited on the distributing roll 94 is controlled by adjusting the glue drum 93 rela tive thereto by means not shown. As shown in FIG. 5, there are two pairs of cooperating feed rolls 57, 96 and 97, 98 which feed a sheet lifted from the stack by the suction roll 56 to the glue distributing roll '94 where adhesive is applied to the sheet. As shown in FIG. 7, the sheet feed rolls 96 are carried on a shaft 100 and are adapted to be engaged by the pair of feed rolls 57 which are carried on a bracket 101 attached to the upper end of a pair of pivoted levers 102. Each of levers 102 is pivoted on shaft 62 as is cam follower lever 103 which carries the roller 104 which engages the cam 53, FIG. 5. The cam follower lever 103 has secured thereto a block 105 through which extends the adjusting screw 106 for adjustment of the angular positions of the levers 102. The bracket 101 which supports the feed rolls 57 also supports a feed tongue 108 which is adapted to move under the sheet after it has been picked up by the suction roll 56 in the manner shown in FIG. 6. The feed tongue 108 assists in guiding the sheets between the lower feed rolls 57 and 96 and also includes an air blast passing through a port 108a in the lower face thereof for preventing a second sheet from being fed to the feed rolls 57 and 96 at the same time. The air is supplied through a hose 109 congeiredl to a pressure outlet 166 at one end of pump P,

The cams 53 which actuate the lower feed rolls 57 through levers 102 and 103 are positioned on shaft 28 with respect to the cams 52 which actuate the suction roll 56 so as to move into the position shown in FIG. 6 from the position shown in FIG. 5 after the suction roll 56 has moved up its inclined track thereby picking up the leading flap of the top wrapper of the stack S. Rotation of the earns 53 cause the levers 102 to reciprocate through an angle about pivot 62 thus causing the feed roll 57 to cyclically engage and disengage with respect to the upper feed roll 96. When roll 57 engages roll 96, these rolls cooperate to transport a sheet to be glued up to the upper feed rolls 97 and 98 which continue to transport the sheet past a paper guide roll 110, FIG. 5, and bring the sheet into engagement with the glue distributing roll 94. The sheet moves upwardly against the surface of glue distributing roll 94 and is stripped from that roll by stripping blades 111 which are pivoted on a shaft 112 and arranged in series therealong. The stripping blades 111 are springbiased so that the blades will conform to the circumference of the distributing roll 94. As the leading edge of the sheet leaves the stripping blades 111, it is engaged by a blast of air from a pipe 113, connected to pressure outlet 166 by hose 114, which forces the sheet onto a perforated suction belt 115 of a suction conveyor which leads to a box wrapping machine.

The belt 115 passes over the conveyor nose 116 which is hinged at 117 so that the end of the conveyor may be raised by rotating the support member 118 about its lower pivot 119. The conveyor belt 115 is driven intermittently by rollers 121 and 122, the opposite ends of which are journaled for rotation on the spaced support members 118, only one of which is shown in FIG. 5. The conveyor roll 121, the feed roll 96 and the feed roll 97 are all driven rolls whereas their cooperating rolls 122, 57 and 98 respectively are all idler rolls. The drive for feed roll 96, FIG. 5, is from shaft 28, FIG. 2, by way of sprocket 126, chain 127, multiplying sprocket 128, chain 130 and sprocket 131 carried by roller shaft 100 which carries the feed rolls 96, FIG. 11. Thus it will be seen that the roll 96 runs only when the single revolution clutch C, FIGS. 11 and 11a, has been engaged. The glue distributing roll '94, the glue drum 93, the upper pair of feed rolls 97 and 98 and roll 96 run all the time the machine motor is running, the drive for these rolls being from a sprocket 135 secured to continuously rotating shaft 23 and through a chain 136 to a sprocket 137 secured to a shaft 94a which carries the distributing roll 94. The drive for feed roll 97 is by way of a gear train 140 from shaft 94a and the drive for the glue drum 93 and the paper guide roll 110 is from gears 138 and 139 respectively carried on shaft 94a, FIG. 11. It will be seen from FIG. 11 that the idler feed rolls 57 and 98 run only when they are in engagement with their cooperating feed rolls 96 and 97, respectively.

The intermittent action of the conveyor drive rolls 121 and 122 is produced by engagement and disengagement of jaw clutch members 141 and 142, FIG. 11. Clutch member 141 is secured to the continuously rotating shaft 23 while the mating clutch member 142 is free on shaft 23. The clutch member 142 is provided with a sprocket 142a which engages a chain 145 which passes over one sprocket of a double sprocket 146, the other sprocket of which engages a chain 148. The chain 148 passes around a sprocket 149 which is adapted to drive through a gear train 159 to shaft 121a which carries the conveyor drive roll 121. The movable clutch member 141 is adapted to be operated by a lever 155 which is pivoted on a stud 156. A starting dog 157 is carried on the shaft 28 and when shaft 28 makes one revolution, the dog 157 will engage one end of lever 155 causing it to pivot about the stud 156 and causing the clutch member 141 to engage the clutch teeth on the cooperating clutch member 142. A detent comprising members 159 and 160 associated with the lower end of lever 155 keep the teeth of the clutch members 141 and 142 in engagement until a second dog 163, which is a-djustably mounted on shaft 28, engages the lever 155 moving it in the opposite direction about its pivot 156 and thus bringing about disengagement of the teeth on clutch members 141 and 142. It will be noted that shaft 23 is provided with a hand wheel 165 which enables the machine to be turned over by hand without turning on the drive motor 15. It is also to be noted that the pump P, FIG. 1, is driven by a separate motor M and thus the vacuum in line 82 and the pressure in connection 166 are available to simulate actual operating conditions while the machine is being turned over by hand.

As previously described, the idler feed rolls 57 are cyclically brought into engagement with the driving feed rolls 96 through the reciprocation of levers 102 under the operation of cams 53, FIG. 5. The idler feed rolls 98 are continuously maintained in engagement with the upper drive feed rolls 97. The journals of rolls 98 are supported between a pair of arms 168 (FIG. 5) which are pivoted at 169 on blocks 170. A pair of flat springs 171, secured at one end to blocks 170, exert pressure on the arms 168 to assure contact between the rolls 98 and 97. The opposite ends of arms 168 are provided with set screws 172 to increase the spring pressure if required. The upper feed rolls 98 extend through openings in an upper guide plate 174 which cooperates with a lower guide plate 175 having an opening through which the feed rolls 97 extend thus permitting engagement between rolls 97 and 98 for feed of paper between the guide plates 174 and 175. The ends of the upper guide plate 174 are carried by the corresponding support members 118 which can be pivoted about the pivot 119 thus providing access to the paper feed plates 174 and 175. When the supports 118 have been rotated in a counterclockwise direction about the pivot 119, the upper guide plate 174 is accessible for washing and the lower guide plate 175 can then be removed from the machine for washing. The lower guide plate 175 is carried by a pair of bars 176 and 177 which rest on hangers 178 at the opposite sides of the machine for easy removal of the plate 175.

Referring to. FIG. 6, there is illustrated a sheet of paper S with its leading flap or panel pinched between the lower pair of feed rolls 96 and 57 at the zero position of the box Wrapping system. Upon initiation of the next cycle of the system, the downwardly hanging portion a of the sheet known in the art as the corner lap, will come under the influence of an up-draft of air shown by the arrow which will blow the corner lap portions a of the sheet S upwardly against the portion bracketed at 174a of the upper paper feed plate 174. By blowing the air directly against the upper plate portion 174a, this insures that the downwardly hanging portions of the sheet which are not between the feed rolls 57 and 96 will be blown against the upper plate 174a in order to prevent the sheet from becoming fouled on the lower plate 175. The air blast blows the sheet against the upper plate portion 174a while the latter controls the position of entry of the sheet into the throat between the upper plate 174 and the lower plate 175. Thus it will be seen that the combination of the air blast with the overhanging portion 174a of the upper plate provides an improved arrangement for accurate feeding of the sheets without fouling. This is particularly desirable since the fouling of a sheet in the gluer of a box wrapping system will require that the entire system be shut down to correct this ditficulty thus resulting in loss of box production time.

The blast of air for blowing the downwardly hanging portions a of the sheet S against the upper plate portion 174a is provided by a pair of fans 180 which supply air through passages 180a to a pair of ducts 181, 182, FIG. 7. As may be seen, the duct 181 comprises a pair of front and back plates 181a which are joined at their edges to bar members 181]) and 181e, the upper end of front plate 181a having been broken away for purposes of clarity. It will be noted that the upper end of elongated member 181s is cut at an angle and in cooperation with triangular block member 181d forms an angular passage 181e at the top of duct 181. The angular passage 181e directs a blast of air in the direction of the rolls 96, i.e., the center line of the sheets, whereas the straight passage 181] on the opposite side of the triangular block 181d will direct a blast of air in a vertical direction. Thus, it will be seen that with this arrangement for diverting a portion of the air blast along an angular direction that even wrapper sheets for shallow boxes, i.e., those having narrow flaps or panels or even the type which are positioned completely between the vertical air ducts 181, 182, will come under the influence of the air stream. The left-hand duct 182 shown in FIG. 7 is of the same construction as the duct 181 with the exception that the angular passage is directed to the right as shown in FIG. 7 rather than to the left as is the case for the angular passage in duct 181. Thus, it will be seen that both of the angular passages in the ducts 181 and 182 are directed toward the feed rolls 96 so as to provide the proper support for the opposite edges of the sheet as it is fed into the feed rolls from the stack of sheets.

The stack of sheets is supported on a tray 185 and the leading edges of the sheets S engage a vertical guide bar 186. The air ducts 181 and 182 are spaced from their rear support bars 187 by vertical guide members 188 which have the same thickness as the center vertical guide member 186 and are aligned therewith. The vertical guide members 188 are slotted at 18811 and are adapted to slide over mounting fins 1881; out from behind the corresponding ducts 181 and 182 to cooperate with the center guide 186 for guiding the leading edge of the larger sheets and preventing them from cocking. When smaller sheets are being fed, the vertical guides 188 are adapted to slide behind the respective ducts 181 and 182 and the latter are adapted to be moved toward the center guide 186 to accommodate the sheets of smaller size.

Referring to FIGS. 2, 7 and 8, it will be seen that the stack of sheets is carried on the tray or table 185. The table 185 is made up of two sheet metal pieces reinforced at its outer edges by heavy structural members 189, FIG. 7. Along the centerline of the tray 185 is a pair of spaced flanges 185a, 185a formed by down-turned portions of the sheet metal table 185. The purpose of the flanges 185a will hereinafter be pointed out. Projecting from the opposite sides of the table 185 are two pairs of heavy rods 191, 192 which extend into pairs of plates 193 which are secured together on opposite sides of vertical support bars 194 carried by each side frame of the machine. Each pair of plates 193 is secured together to form a unit and the units are secured to angle members 196 which, in turn, are secured to sprocket chains 197 by bolts 198 which pass through links in the chains and through one side of the angle members 196, FIGS. 2 and 8. Also positioned between the spaced plates 193 are roller members 200 and 201 which are rotatably affixed to the plates and which engage the opposite sides of the vertical support bars 194. Thus, it will be seen that the spaced plates 193 provide a trolley arrangement adapted to ride on the tracks 194. The table 185 for the wrappers is cantilevered with respect to this trolley and by reason of this arrangement, it is possible for the table 185 to hold substantially heavier stacks of sheets than on previous machines. It has been found that this construction for supporting a table for the stack of wrappers is capable of holding more than twice the weight of paper stacks on corresponding previous machines.

By supporting the table 185 on heavy rods 191 and 192, there is provided an arrangement which greatly simplifies shipment of the machine. It will be noted that the table, when in its horizontal position, extends beyond the vertical side frame 11, FIG. 2, of the machine. By raising the table to its upper position and removing the top rods 191 from the trolley plates 193, the table may be pivoted from its horizontal position to a substantially vertical position thus bringing the table 185 beneath the overhanging portion of the plate 11 as shown in phantom lines in FIG. 2. In addition, by removing the upper pins 191 on 'both sides of the machine, the rollers 200 and 201, FIG. 8, likewise may be removed.

The table 185 is elevated through the chains 197 which pass around upper sprockets 204 and lower sprockets 205, the latter being carried by a shaft 206 which is driven from a countershaft 207 by way of sprockets 208, 209 and chain 210, as shown in FIG. 11. As may be seen in FIGS. 8 and 11, shaft 207 carries a second sprocket 211 around which passes a chain 212 which also passes around a sprocket 213 carried on a shaft 214 which also has connected thereto a hand wheel 215 for manually raising or lowering the table height. The table height is adapted to be automatically raised through a clutch arrangement 217 diagrammatically illustrated by the rectangle in FIG. 11 and the parts of which are illustrated in detail in FIG. 8, as described below.

The stack height is sensed through a roller 220, FIG. 2, which engages the rear end of the stack of sheets S. This does not interfere with air blasts which are directed from the multiple ports of air blocks 221 which are spaced on the opposite sides of the upstanding tongue 186a of member 186, FIGS. 3 and 7, for directing air pressure against the forward edge of the sheets to rifile the edges and assist in separating the top sheet from the remainder of the stack. The air blast blocks 221 are supplied with air from hose 222 and separate the sheets so that they can be more readily picked up by the suction roll 56, FIG. 3. The brushes 224 (FIGS. 5 and 7) are manually adjustable about a shaft 225 mounted upon the upper rear support bar 187 and also serve to prevent double sheet feeding.

The stack height sensing roller 220 is carried by an assembly which includes a pair of outer members 230, FIG. 10, which are secured to a pair of inner plates 231 separated at one end by a roller 232 and at the other end by an elongated link 233, with all of said elements being secured together to form said assembly by connecting members 234 (FIG. 10). This pile height sensing roller assembly is mounted for vertical movement on a bar 235 which is parallel to the link 233 and has an elongated notch 235a near the top thereof which is adapted to receive a roller member 230a carried by the spaced arms 230. The notch 235a, in cooperation with the roller member 230a, prevents the pile height sensing assembly from sliding all of the way down the vertical bar 235 when the table is lowered and is being replenished with sheets. The vertical bar 235 is supported at its lower end on an elongated tubular member 237 through which extends a rod 238 thus permitting adjustment of the sensing assembly to accommodate sheets of various length. The rod 238 is secured at one end to the back of the frame of the machine 10 and the other end of the rod 238 is provided with an adjustable foot 239 which rests on the floor and supports the rod 238 in horizontal position, FIG. 2. As previously mentioned in connection with FIG. 7 and as shown in FIG. 9, the table is constructed in two pieces with flanges 185a extending along the centerline of the table. The flanges 185a form a slot along the centerline of the table through which the vertical members 233 and 235 extend. The flanges 185a provide lateral support for the vertical bars 233 and 235 and the elongated tubular member 237 provides longitudinal support for members 233 and 235.

As may be seen in FIGS. 2 and 9, attached to the lower end of the vertical member 235 is a microswitch 240. Secured to the lower end of the vertically movable member 233 is an adjustable button 241 which is adapted to engage the actuator 240a of the microswitch 240. The pile height is sensed through the roller 220 on the top of the stack S and the associated linkage 230, 233, and 241 to act on the microswitch 240.

The microswitch 240 is a normally closed switch. Thus, when the pile height is low, the button 241 will be out of engagement with the actuator 240a and the switch 240 will remain closed. When the switch 240 is closed, it completes an electrical circuit to a pull solenoid 245 through wires 244 as shown in FIG. 8. The solenoid 245, when energized, rotates a lever 246 about a central pivot 247 causing a latch member 248 to become disengaged with respect to a lock member 249. The lock member 249 is carried by an arm member 250 which, in turn, is carried by shaft 214 within the clutch arrangement 217. The arm 250 is connected by a link 251 to one end of a lever 252 which is pivoted at its opposite end on a pin 253 carried by the side frame 12 of the machine. The lever 252 carries a cam follower 252a which engages an eccentric 254 on shaft 28. When the latch member 2 48 comes out of engagement with the lock member 249, the link 251 is allowed to adjust the arm 250 in accordance with rotary motion of the eccentric 254 so that a pawl 256 carried by arm 250 will intermittently rotate in a clockwise direction about a ratchet 257 carried by shaft 214, the eccentric 254 being driven intermittently in one revolution movements by the shaft 28 as explained hereinbefore. When the eccentric 254 rotates to its maximum throw, as shown in FIG. 8, the lever 252 will be raised to its maximum upper position thereby raising the link 251. When link 251 is raised, it, in turn, will raise the end of arm 250 causing the pawl 256 to rotate the ratchet 257 which, in turn, rotates shaft 214. Rotation of shaft 214 causes rotation of sprocket 213 which imparts rotation to shaft 207 by way of chain 212 and sprocket 211. Rotation of shaft 207 and sprocket 208 carried thereon imparts rotation through chain 210 to sprocket 205 on shaft 206 thus causing the chains 197 to elevate the table 185. When the stack height is at the proper level, the microswitch 240 will be held open by the button 241, FIG. 9, which will have been raised due to the raising of the stack height. Since the switch 240 will then be open, the solenoid 245 will not be energized and the latch member 248 will remain in engagement with the lock member 249 thus preventing the arm 250 and its associated linkage 251, 252 from following the action of the eccentric 254.

From the foregoing, it is believed that the operation of the sheet feeding and gluing system is clearly described. It shall be understood that the invention is not limited to the specific arrangements shown and that changes and modifications may be made within the scope of the appended claims.

What is claimed is:

1. A method of feeding paper sheets having laterally projecting side flaps one by one from the top of a horizontally positioned stack to a gluing machine comprising the steps of applying a first air blast horizontally of the leading edges of the sheets at the top of the stack for separation of the top sheet at its leading edge, applying suction to the mid-portion of the upper surface of the leading end of the top sheet to lift it from the stack, applying a force to the lower surface of the leading end of the sheet after the leading end of the sheet has been lifted by the suction applied to the upper surface for moving the leading end of the sheet between upper and lower guide plates, applying vertical air blasts to the lower surfaces of each of the laterally projecting side flaps of the sheet to force the side flaps upwardly against the upper guide plate and thus control entry of the side flaps between the guide plates.

2. The method according to claim 1 where the air blasts applied to the lower surface of the sheet include portions directed in an angular direction, upwardly and toward the longitudinal center line of the sheet, the air blasts comprising wide bands extending for a substantial transverse distance at the opposite lateral edges of the sheet.

3. Sheet feeding apparatus for feeding sheets one at a time to a gluing machine comprising means for separating a stack of sheets, means for applying a first air blast against the leading edges of the sheets at the top of the stack for separation of the top sheet at its leading edge, a pair of upper and lower guide plates disposed above the top of the stack, said upper plate having a portion extending beyond said lower plate in the direction of the stack, means for applying suction to the upper surface of the leading end of the top sheet to lift it from the stack, means for applying a force to the lower surface of the leading end of the sheet to move the leading end between said upper and lower guide plates, and means for applying a second air blast to the lower surface of the sides of the sheet to force the sides upwardly against said extending portion of said upper guide plate thereby controlling entry of the sides of the sheet between said guide plates.

4. Sheet feeding apparatus according to claim 3 wherein said last-named means comprises a pair of vertical air ducts having their outlets extending along the leading end of the stack.

5. Sheet feeding apparatus according to claim 4 wherein said air ducts include a flow passage extending at an angle toward the center line of the stack.

6. Sheet feeding apparatus according to claim 3 wherein said upper plate is pivotally carried relative to said lower plate for access between said plates and said lower plate is removably carried by stationary supports beneath said upper plate.

7. Sheet feeding apparatus according to claim 3 including a gluing machine, and means for manually advancing the sheets through said sheet feeding apparatus and said gluing machine while maintaining said air blast and said suction.

8. Sheet feeding apparatus comprising a table for supporting a horizontal stack of sheets, a vertical guide member engaging the central portion of the leading edge of the stack and extending upwardly from the bottom through the full height of the stack so as to maintain the leading edge of each sheet in the stack in vertical alignment, and a pair of vertical side guides engaging the stack at the sides of the leading edge of the stack, said side guides each including at least one vertical air passage therein and having an outlet therefor arranged to direct an air blast upwardly substantially within the plane of the leading edge of the stack.

9. Sheet feeding apparatus according to claim 8 wherein said air passage is arranged so as to direct said air blast in an inward angular direction with respect to the center line of the stack.

10. Sheet feeding apparatus according to claim 9 wherein said side guides comprise ducts having a pair of outlets on their uppermost surfaces.

11. Sheet feeding apparatus comprising a table for supporting a vertical stack of sheets, means for raising said table to bring the top sheet on the stack into a predetermined position relative to sheet feeding means, said table having a slot extending lengthwise thereof, and stack height sensing means comprising a stationary member supported from beneath said table and extending upwardly through said slot, means for adjusting said stationary member lengthwise of said slot to a position adjacent the rear of the stack of sheets in accordance with the length thereof, a movable member carried by said stationary member, a sensing height member carried by said movable member and engaging the top of the stack of sheets at the rear thereof, and a switch and switch actuating means each respectively carried by one of said members in cooperative relation for controlling the operation of said switch in accordance with the height of the stack, said sugiich being in circuit with said means for raising said ta e.

12. Sheet feeding apparatus according to claim 11 wherein said movable member comprises elongated structure extending through said slot in said table.

13. Sheet feeding apparatus according to claim 11 wherein said height sensing member comprises a roller.

14. Sheet feeding apparatus according to claim 11 wherein said stationary member includes a notch adjacent the top thereof, and structure carried by said movable member and extending into said notch to limit relative movement between said members.

15. Sheet feeding apparatus according to claim 11 wherein said means for raising said table includes trolley means and means for moving sadi trolley means vertically along a pair of tracks, said table being carried at one end by said trolley means.

16. Sheet feeding apparatus according to claim 15 wherein said table is connected to said trolley means at each side thereof by a pair of supporting members, and one of said supporting members is removable to permit pivoting of said table about the axis of the other of said supporting members from a horizontal position outwardly to a substantially vertical position for shipment of said apparatus.

17. Apparatus for feeding sheets singularly from a stack of sheets comprising a frame, table means for supporting the stack, means for mounting said table on said frame for relative vertical motion, means for elevating said table, means for controlling table elevation so that the top of the stack remains at a substantially constant elevation, means for separating the leading edge of the top sheet, sheet guide means mounted on said frame for leading the sheet being fed away from the stack, said guide means comprising a pair of closely spaced guide plates arranged in a substantially parallel relationship, sheet lifting means for lifting the leading end of the top sheet into position for entering between said guide plates, sheet feed means for advancing the lifted leading end of the sheet between said guide plates, and auxiliary sheet holding means for holding the lifted sheet up against the uppermost of said guide plates.

18. The apparatus of claim 17, wherein said sheet lifting means is an oscillating suction roller.

19. The apparatus of claim 17, wherein said auxiliary sheet holding means comprises a pair of vertical air ducts having outlets at the leading end of the stack.

References Cited by the Examiner UNITED STATES PATENTS 1,736,483 11/1929 Broadmeyer 27 l58 2,402,442 6/ 1946 Perry 27l26 2,631,850 3/1953 Smith 27l62 2,849,231 8/1958 Reguly et al. 27l11 3,083,011 3/1963 Saul 27126 20 ROBERT B. REEVES, Primary Examiner.

M. HENSON WOOD, JR., Examiner.

W. F. MCCARTHY, Assistant Examiner. 

1. A METHOD OF FEEDING PAPER SHEETS HAVING LATERALLY PROJECTING SIDE FLAPS ONE BY ONE FROM THE TOP OF A HORIZONTALLY POSITIONED STACK TO A GLUING MACHINE COMPRISING THE STEPS OF APPLYING A FIRST AIR BLAST HORIZONTALLY OF THE LEADING EDGES OF THE SHEETS AT THE TOP OF THE STACK FOR SEPARATION OF THE TOP SHEET AT ITS LEADING EDGE, APPLYING SUCTION TO THE MID-PORTION OF THE UPPER SURFACE OF THE LEADING END OF THE TOP SHEET TO LIFT IT FROM THE STACK, APPLYING A FORCE TO THE LOWER SURFACE OF THE LEADING END OF THE SHEET AFTER THE LEADING END OF THE SHEET HAS BEEN LIFTED BY THE SUCTION APPLIED TO THE UPPER SURFACE FOR MOVING THE LEADING END OF THE SHEET BETWEEN UPPER AND LOWER GUIDE PLATES, APPLYING VERTICAL AIR BLASTS TO THE LOWER SURFACES OF EACH OF THE LATERALLY PROJECTING SIDE FLAPS OF THE SHEET TO FORCE OF SIDE FLAPS UPWARDLY AGAINST THE UPPER GUIDE PLATE AND THUS CONTROL ENTRY OF THE SIDE FLAPS BETWEEN THE GUIDE PLATES. 